Polymeric coating composition containing a metal salt of an organic carboxylic acid



United States Patent POLYMERIC COATING COMPOSITION CONTAIN- IN G A METALSALT OF AN ORGANIC CARBOX- YLIC ACID Charles I. Sullivan, Melrose, andFrancis L. McCarthy,

Quincy, Mass., assignors to A. E. Staley Manufacturing Company, Decatur,Ill., a corporation of Delaware No Drawing. Continuation-impart ofapplication Ser. No. 404,911, Oct. 19, 1964. This application July 12,1965, Ser. No. 471,405

18 Claims. (Cl. 260-285) ABSTRACT OF THE DISCLOSURE A polish compositioncomprising (1) a water dispersible polyvalent metal salt of an organiccarboxylic acid having from 1 to 4 acid groups in a concentrationsufficient to impart leveling and selective removability to said polishcomposition and (2) an aqueous emulsion of a synthetic addition polymercomprising at least one hard monomer selected from the group consistingof monovinyl aromatic compound, alpha, beta-ethylenically unsaturatednitrile and alkyl ester of alpha, beta-ethylenically unsaturatedcarboxylic acid, said polymer having a Tg of at least 25 C. at anemulsifier content of 5% by weight of the polymeric component.

This application is a continuation-in-part of copending application Ser.No. 404,911 filed Oct. 19, 1964.

This invention relates to a new floor polish. More particularly, thisinvention relates to a new floor polish (either buffable or dry bright),which is neither dulled nor removed by soap (or detergent) and water,but which can be readily removed from the flooring. This invention isalso concerned with a method for treating and preserving flooringmaterials.

The ideal floor polish is a well-balanced composition having thefollowing properties: bufiable; spreads easily; levels well; driesrapidly; has high gloss; has good clarity; has little or no tendency todiscolor; has resistance to spilled household liquids; has resistance towater spotting; has resistance to scuifing and scratching; has a longlife; can be washed with soap (including detergents) and water withoutbeing removed or dulled; can be removed easily, when desired, withoutany deleterious effect on the flooring; and can be recoated with asecond layer of polish Without removal of the first layer. In recentyears, floor polish formulators have turned to floor polishes based onpolymers of styrene and/or acrylates in an attempt to find productshaving a maximum number of these desirable properties. While these floorpolishes have met with considerable commercial success, none of them hashad all of the above properties. Regardless of what other properties theformulator was willing to sacrifice, it has always been necessary tosacrifice either soap and water resistance or removability. So far asknown, until now, commercially available floor polishes, if resistant todulling and removal by soap and water, either cannot be removeduniformly from the floor or require extensive abrading action that isdeleterious to linoleum, asphalt, rubber, vinyl and other tile and otherso-called hardsurface resilient flooring. For example, hydrocarbon basedsolvents tend to remove the pigmentation from the surface of theflooring in such a manner that a subsequently applied coat of polish hasa dull appearance. 0n the other hand, strenuous scouring means theabrasion of the flooring.

In addition to the removability problems discussed in the precedingparagraph, it is well-known that synthetic polymers based on styreneand/ or acrylates are generally not considered to be suitable for use inbuflable floor 3,403,119 Patented Sept. 24, 1968 polishes. In theFebruary 1964 issue of Paint Manufacture, volume 34, No. 2, pages 45-49and 53, R. Zdanowski of the Rohm & Haas Laboratory points with pride tothe fact that a popular commercial buifable polish could have up to 30%of the Fischer-Tropsch polyethylene wax formulation replaced withRhoplex B-83 polymer emulsion and still retain buffabilitycharacteristics of the wax product.

The object of this invention is to provide a floor polish (eitherbuffable or dry bright) that forms a protective coating resistant towashing, and to soap and water, yet is easily, completely and uniformlyremovable with simple, safe materials that have no deleterious effectson the flooring. A further object of this invention is to provide abuffable floor polish having all of the above-described qualities to amarked degree. Another object is to provide a polymer emulsioncomposition suitable for a floor polish having the properties alreadymentioned. Other objects will become apparent from the descriptionbelow.

The poor detergent-resistance of most floor polishes, it has been found,is due in large part to the presence of alkali-soluble resins andemulsifiers in the floor polish. As pointed out by Zdanowski,alkali-soluble resins can typically comprise as much as 10 to 16.5percent by weight of the floor polish dry solids. The alkali-solubleresins are necessary to impart to the floor polish the necessaryleveling characteristics and glass. Emulsifiers are, of course,necessary in order to produce the synthetic polymers having the properparticle size and in order to impart the necessary coalescing propertiesand gloss.

Recent attempts to build hydrophobic qualities into floor polishes byusing polymers based on aminoalkyl esters of (meth)acrylic acid have metwith limited success. Floor polishes based on these polymers, asoriginally otfered to the trade, were supposed to be removable using anacidic stripper. However, many of the acidic strippers had deleteriouseffects on the flooring and/or were incapable of completely removingapplied polishes after they had aged a month or more. Somewhat betterremovability has been obtained using machine scrubbing with standardtripolyphosphate cleaners.

U.S. Patent 2,754,280 to Brown et al. discloses that nonionic emulsionsof copolymers of esters of acrylic acid and/or methacrylic acid and anacid monomer (methacrylic acid, acrylic acid or itaconic acid) andsuitable polyvalent metal compounds can be applied as a coating to asurface. The patentees state that the polyvalent metal compoundsionically cross-link free (unesterified) carboxyl groups. The resultantproducts are stated to be water-insoluble and chemically resistant andto have the properties of the thermosetting resin. No one has suggestedusing a polymeric system of this type in a floor polish. From thepatentees disclosure, it would appear that it would be impossible toremove the ionically cross-linked polymeric material from the substrateand, accordingly, this type of polymeric system would not appear to beuseful in a floor polish composition.

The nonionic emulsion polymer-polyvalent metal compound described in thepreceding paragraph would not be considered suitable for use in a floorpolish because of the known interaction of polyvalent metal compoundsand alkali-soluble resins at the alkaline pH normally required for afloor polish. At an acidic pH the alkali-soluble resin alone (withoutany polyvalent metal salts) is insoluble and therefore, incapable ofperforming its functions of dispersing, leveling and coalescing in thefloor polish.

U.S. Patent 3,026,281 to Harren et al. discloses that polyvalent metalcompounds react with relatively low molecular weight polymericpolyanionic water-soluble materials (i.e. alkali-soluble resins of thetype used in floor polish formulations) to form thixotropic thickeningagents useful at an alkaline pH. Higher molecular weight polyanionicalkali-soluble materials are said by the patentees to be unsuitablesince polyvalent metal compounds precipitate the higher molecular weightmaterials. Reaction products of alkali-soluble resin and polyvalentmetal compounds would be expected to have no use in a typical floorpolish.

It has now been found that the objects of this invention can beaccomplished by providing an acidic floor polish comprising polyvalentmetal salt of an organic acid, which is at least partially soluble inwater at an acidic pH, and an aqueous emulsion of addition polymer andemulsifier. So far as is known, the floor polish of this invention isthe first acidic floor polish, all others being alkaline. Surprisingly,the acidic floor polish of this invention has no deleterious effects onflooring materials as might have been expected from previous experienceswith acidic strippers.

The polyvalent metal salts which are soluble in water at an acid pH seemto serve as leveling agents in the acidic floor polish formulations ofthis invention and obviate the necessity of using alkali-soluble resins.As pointed out above, conventional alkali-soluble resins are insolublein aqueous acid. Omission of the alkali-soluble resin eliminates, it isbelieved, one of the principal sources of detergent sensitivity of theconventional applied floor polishes.

Surprisingly, replacement of alkali-soluble resin with polyvalent metalcompound leads to floor polishes, based on synthetic polymers, which arebutfable with a much lower concentration of wax than anyone hasheretofore believed possible. For example, Zdanowski, supra, indicatesthat, whereas a 7-to-3 solids ratio of wax to Rhoplex B83 polymeremulsion yields a buffable floor polish having the same characteristicsas an all wax polish, a 1-to-1 ratio yields a floor polish having onlyfair buffability characteristics. On the other hand, commerciallydesirable floor polishes having very good bufiability characteristicscan be prepared using a 3 to 7 ratio of wax to synthetic polymer whenthe alkali-soluble resin is omitted and, a suitable polyvalent metalsalt of an organic acid and the proper polymer emulsion are used at anacid pH, in accordance with this invention.

It is believed that there are a number of factors which contribute tothe unique buffability characteristics of the floor polishes of thisinvention which make it possible to replace more Wax with syntheticpolymer than previously deemed possible without sacrificing buffability.Omission of alkali-soluble resins, which dry (alone) to form a friablematerial, seems to convert the floor polish matrix to a structure whichis more amenable to flow under pressure. Many of the polyvalent metalsalts of organic acids utilizable in this invention apparently form amobile matrix which permits the applied polish to deform under pressure.

As a general matter, buffability of a wax-containing floor polish mayalso be attributable to the tendency of the wax to bleed out of theapplied polymeric matrix of the polish. Accordingly, organic acid saltsof polyvalent metal augment the wax.

Two other important factors that affect buffability, are discussedbelow. These are the relatively high concentration of surface activeagents utilized in the floor polish of this invention and the degree ofhardness of the synthetic polymers.

In this invention, the particular polyvalent metal compounds perform atleast two other important functions, in addition to leveling andaugmenting the action of Wax. Some of the polyvalent metal compoundapparently reacts with free carboxyl groups of carboxyl-containing floorpolishes to render applied floor polishes based on the above describedsystem resistant to conventional detergents. Subsequently, when it isdesired to remove the applied floor polish, the polyvalent metalcompound aids in the removal of the applied floor polish with a suitablealkaline stripper such as a mixture of detergent and water-miscibleorganic solvent. superficially, these last two functions appearinconsistent. However, this illustrates the selectivity of operation ofthe polyvalent metal salts in this invention. For example, two acidicfloor polishes, which were essentially the same except that one contained polyvalent metal salt of an organic acid and one did not containthis component, were applied to a suitable substrate. In each case, thesynthetic polymer employed contained approximately 3% by weight acidmonomer units. The applied floor polish containing no polyvalent metalsalt was removable using two of five commercially sold floor polishstrippers in the recommended manner; the other three strippers had noeffect. However, even at twice the recommended concentration, none ofthe five strippers had an effect on the applied polish containingpolyvalent metal salt. On the other hand, a new stripper, of the typedescribed below, readily removed the polish containing the polyvalentmetal salt, but only partly removed the polish having no polyvalentmetal salt.

The removability imparted by polyvalent metal compounds is illustratedfurther by floor polishes of this invention which contain a lowconcentration of acid monomer in the synthetic polymer. Two floorpolishes of the type described in the preceding paragraph (onecontaining polyvalent metal salt of an organic acid and one without)were prepared from a synthetic polymer of the type employed in thepreceding paragraph but with no free carboxyl groups. The applied polishcontaining no polyvalent metal compound was not removable with anydetergent or strippper tried (including the strippers normallyutilizable in this invention) While the applied polish containingpolyvalent metal compound was removable with the strippers normallyutilizable in this invention.

The detergent resistance imparted by polyvalent metal compounds isillustrated further by floor polishes of this invention which contain ahigh concentration of acid monomer in the synthetic polymer (normallyvery sensitive to water). Two fioor polishes of the type described inthe preceding two paragra hs were prepared from a synthetic polymerwhich contained about fifteen percent by weight acid monomer units.After aging one week, the applied floor polish containing no polyvalentmetal compounds was removable with detergents (exhibiting the expectedwater sensitivity) while the applied polish containing polyvalent metalcompound wa substantially unaffected.

Acordingly, it can be seen that, in the floor polishes of thisinvention, the polyvalent metal compound imparts (1) resistance toconventional detergents and (2) removability with certain classes offloor-polish strippers. The exact mechanism through which the polyvalentmetal compound performs these functions is not clear. However, it isbelieved that the detergent resistance of fioor polishes, which containsynthetic polymers having free carboxyl groups and are normallydetergent sensitive, is due in part to ionic cross-linking of the freecarboxyl groups through the polyvalent metal. However, the removabilityof applied floor polishes of this invention does not seem to bedependent on the destruction of ionic cross-links. As pointed out above,the polyvalent metal compound imparts removability even to acidic floorpolishes having no free carboxyl groups and insensitive to strippers andto detergent. The new polish-strippers of this invention apparentlyswell the polyvalent metal compound. As the polyvalent metal compoundswells, the bond between polymer particles and between the polish layerand substrate are loosened, thereby enabling complete removal.

Polyvalent metal salts of organic acids useful in this invention whichare at least partially soluble in water at an acidic pH (i.e.,dispersible in water) include zinc acetate, Zinc caprylate, zinccitrate, zinc formate, zinc isovalerate, zinc lactate, zinc malate, zincoxalate, zinc propionate, zinc salicylate, basic aluminum acetate,aluminum citrate, aluminum diformate, aluminum formacetate, aluminumtriformate, titanium oxalate, zirconium acetate, zirconium lactate,barium acetate, calcium acetate, calcium benzoate, calcium gluconate,calcium lactate, calcium mandelate, calcium propionate, calciumsalicylate, calcium succinate, calcium tartrate, magnesium acetate,magnesium acetyl salicylate, magnesium benzoate, dibasic magnesiumcitrate, magnesium formate, magnesium gluconate, magnesium lactate,magnesium salicylate, strontium acetate, strontium salicylate, leadacetate, lead formate, lead salicylate, cobaltous acetate, cobaltouscitrate, cobaltous formate, cobaltous succinate, chromic acetate,chromous oxalate, cupric acetate, cupric gluconate, cupric lactate, etc.In general, the colorless salts are preferred. Best results have beenattained using salts of zinc, cadmium and aluminum, preferably theacetates. Zinc acetate is particularly preferred. If desired, the saltmay be formed in situ, e.g., adding acetic anhydride or acid to apolymer emulsion containing zinc oxide.

These compounds can comprise from about 5 to 100 parts by weight ofmetal salt per 100 parts by weight of emulsion polymer solids. As theconcentration of polyvalent metal salt of an organic acid increases upto a point, the detergent resistance of the applied polish increases.However, at the same time the tendency of the applied polish to lose itsgloss and become hazy, also increases. Any loss in gloss can, in turn,be overcome by increasing the nonionic emulsifier content of the polish.However, as the emulsifier content increases, the applied polish becomesprogressively softer, with attendant disadvantages. For these reasons,the optimum concentration of polyvalent metal compound is considered tobe about to 25 parts by weight per 100 parts by weight of emulsionpolymer solids. At these concentrations of polyvalent metal-organic acidsalt, nonionic emulsifier concentration is preferably kept in the rangeof about 0.5 to 2.0 parts by weight per part by weight of polyvalentmetal compound.

As indicated above, the products of this invention comprise twoessential components which are (1) polyvalent metal salt of an organicacid and (2) an aqueous emulsion of polymer and emulsifier. Forformulation of a floor polish having optimum detergent resistance andremovability, the aqueous emulsion of polymer and emulsifier is furthercharacterized in that the :polymer has a glass transition temperature(Tg) of at least 25 C. at an emulsifier content of 5% by weight of thepolymeric component. The products are further characterized in that thepolish composition is not film-forming at room temperature in theabsence of polish coalescing agents and polish plasticizers.

The glass transition temperature (Tg) of a polymer emulsion may bemeasured, as described by Cahill and McCarthy in Soap and ChemicalSpecialties 30, No. 4, 88 ff. (April 1964). At this temperature, a highmolecular weight thermoplastic polymer changes from a hard, somewhatbrittle form to a rather soft, rubbery form. A number of propertiesundergo a large change within a narrow temperature range, among themtorsional stiffness. Measurements of torsional stiffness are made inaccordance with ASTM Test Method D 1043-51 at a series of temperaturesbridging the transition temperature. These values are plotted and thelinear portions of the curve are extrapolated to an intersection whichis the glass transition temperature Tg.

The Tg of a polymer emulsion is dependent on the concentration ofemulsifier or emulsifiers (weight ratio of emulsifier to polymer) andthe monomer or monomers making up the polymer. Generally, the Tg of apolymer emulsion decreases as the weight ratio of emulsifier to polymerincreases. Since the water sensitivity of a coating deposited from apolymer emulsion increases as the weight ratio of emulsifier to polymerincreases above a certain optimum, polymer emulsions are normallyprepared (emulsion polymerization or emulsification of preformedpolymers) with the smallest concentration of emulsifier that willprovide desired properties (e.g. polymer particle size and polymeremulsion stability). With the emulsifier proportion fixed, the Tg of thepolymer emulsion can then be adjusted by means of the proportions anddistribution of hard monomer and soft monomer in order toform a polymerwhich is film-forming at the desired application temperature, usuallyroom temperature. The Tg of a polymer emulsion increases as theconcentration of hard monomer in the polymer increases and, conversely,decreases as the concentration of soft monomer increases. (The termshard and soft are used herein in reference to polymers formed from themonomers alone, in the way that is common in this technology. SeeRiddle, Acrylic Esters, Reinhold Publishing 1954, page 58 et seq.; alsoU.S. Patent No. 2,795,564. Generally, this refers to the brittle-pointof the polymer, i.e. the temperature at which the polymer breaks onflexing. The hard monomers useful in this invention have brittle pointsin excess of C.)

The concentration of emulsifier in the aqueous polymeric emulsion, theratio of hard monomer to soft monomer, and the specific monomersemployed also have a decided effect on the physical properties ofapplied floor polishes. As pointed out above, normally the higher theconcentration of emulsifier, the more water-sensitive is the appliedcoating. Contrary to this general rule, the emulsifier level hasvirtually no effect on the water-sensitivity of the floor polishes ofthis invention. It was found, however, that as the concentration ofemulsifier was increased, the hardness of the applied coating decreased.If carried too far, the applied polish is too soft, and dirt becomesembedded easily in the polish, thereby shortening the life of thepolish.

The polymeric compositions of this invention have an unusually highconcentration of emulsifier to assure clarity and freedom from haze inthe presence of the polyvalent metal salt. If the concentration ofemulsifier is too low, the preferred polymers of this invention tend todry with somewhat more haze than is'desirable in a floor polish. Toavoid any softening effect of emulsifier added to maintain the desiredclarity and, yet to imp-art the necessary abrasion-resistance to theapplied floor polish, the polymers used in this invention contain arelatively high concentration of hard monomer. Stated differently, thepolymeric component of the invention, is such that it has glasstransition temperature (Tg) of at least C. when compounded with 5% byweight of an emulsifier. Polymers having a Tg below 40 C. impart to thefinal floor polish a tendency to pick up dirt at a faster rate thandesirable thereby decreasing the life of the final polish. The additionof extremely hard waxes, acid soluble resins or additional polyvalentmetal compound to the floor polish can counteract this undesirableproperty. Desirably, the Tg of the polymer at this emulsifier level isat least 40 C. and preferably at least C.

As indicated above, the polymers useful in this invention for thepreparation of a removable, detergent-resistant floor polish must have aTg of at least 25 C. (preferably at least 65 C.) at an emulsifierconcentration of 5% by weight of the polymeric component. For the mostpart these polymers are composed of three different monomer types, i.e.hard monomer, sof monomer and free-carboxyl-containing monomer. Hardmonomer is, of course, essential for preparation of a polymeric emulsionhaving a Tg of at least 40 C. Soft monomer can be omitted, but only atthe expense of using an undesirably high concentration of emulsifier.However, it is far better to use soft monomer since it serves to impartthe proper-film-forming characteristics, i.e. it aids in forming acontinuous, clear, craze-free layer which withstands normal wear, impactand fiexure without cracking.

The function of the free-carboxyl-containing monomer and the effect ofits omission is explained above.

The hard monomer imparts to the polymer and floor polish preparedtherefrom the abrasion-resistance normally expected of the floor polish.The concentration of hard monomer necessary to impart the desiredproperties to the polymer emulsion, can range from 59 to 160% by weightof the polymer. Best results have been obtained using from 60 to 85% byweight hard monomer.

Suitable hard monomers include monovinyl aromatics such as styrene andring-substituted styrene (vinyl toluene, 2,5-dichlorostyrene); alpha,beta-ethyienically unsaturated nitriles such as acrylonitrile andmethacrylonitrile; hard esters of alpha, betaethylenically unsaturatedcarboxylic acid esters such as methyl methacrylate, tertbutylmethacrylate, cyclohexyl acrylate and dimethyl itaconate, dimethylmaleate, etc. Of these the monovinyl aromatics and alpha,beta-ethylenically unsaturated nitriles are preferred. Floor polishescomprised of polymer having a high concentration of monomers of thesetwo classes, particularly mixtures of styrene and acrylonitl'ile, haveexceptional detergent-resistance and other properties desired in a goodfloor polish. The monovinyl aromatics having no saponifisble groups areparticularly useful in imparting detergent-resistance to the floorpolish. The polar nature of the nitrile group enhances the levelingproperties of the final polish and the adhesion to new tile which cansometimes be a problem. Acrylonitrile is particularly useful because ofthe toughness that it imparts to the final polish. Further,acrylonitrile and styrene are both quite inexpensive. For best results,the polymer should contain at least 50% by weight monovinyl aromaticmonomer and/ or nitrile monomer.

On the other hand, as the concentration of hard ester of al ha,beta-ethylenioally unsaturated caboxylic acid in the polymer increases,the floor polish becomes less detergentresistant, is more susceptible towater spotting and consequently must be removed or recoated sooner. Forexample, when methyl methacrylate, the least expensive (although abouttwice the price of acrylonitrile and three times the price of styrene)and most commonly used hard ester monomer, comprises 50% by weight ofthe hard monomers in the polymer, the resultant polish is somewhatdeficient in detergent-resistance. If methyl methacrylate is the onlyhard monomer, the floor polish is relatively prone to water spotting.This is to say that in comparison with polish based on polymers havingover 50% monovinyl aromatic and/ or nitrile, the detergent resistanceand I floor-life expectancy of floor polishes based on polymer having ahigh concentration of hard ester monomer are relatively poor. Yet, eventhese latter polishes have high detergent resistance and removabilitycharacteristics of a relatively high order when compared withcommercially available products. However, the increased cost and poorerproperties will not normally justify the use of the ester monomers inhigh concentration, i.e., over 50% by weight of the hard monomer.

While the soft monomer can comprise up to about 45% by weight of thepolymer, best results have been obtained using from about 10 to byweight. Suitable soft monomers include primary or secondary alkyl estersof acrylic acid containing up to 8 carbon atoms in the alkyl group andprimary or secondary alkyl esters of methacrylic acid containing from 4to 12 carbon atoms in the alkyl group. Representative soft monomers aremethyl acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate,amyl acrylate, hexyl acrylate, heptyl acrylate, 2-ethylhexyl acrylate,butyl methiacrylate, amyl methacrylate, dodecyl methacrylate, etc.

The free carboxyl-containing monomer can comprise up to 25% by weight ofthe polymer. Generally, it is advisable to employ 0.5% to 15% by weightfree carboxyl containing monomer. Best results have been obtained with 1to 5% by weight free carboxyl monomer. Suitable carboxyl containingmonomers include acrylic acid, methacrylic acid, ethacrylic acid,itaconic acid, monobutyl itaconate, etc.

Briefly the aqueous copolymers of this invention can be prepared byeither forming an aqueous emulsion premix, addlng the monomers to bepolymerized and catalysts to the emulsion premix and polymerizing saidmonomers or, alternatively, by emulsifying a prepared polymer. Theformer method is preferred since it is more convenient, yields productshaving more uniform properties and is susceptible of more precisecontrol. It is particularly difficult to prepare polymers having thenecessary particle size by emulsification of prepared polymer. If theaverage particle size of the polymer particle is more than 2 microns,the final polish lacks the gloss required of a good floor polish.

The emulsifiers useful for dispersal or emulsification of monomer orpolymer may be chosen from a wide variety of nonionic surface activeagents and anionic surface active agents particularly anionic surfaceactive agents having a polyoxye-thylene chain of at least 5 oxyethyleneunits. Two or more surface active agents are frequently used, of one orboth types, and it is preferred to use both an [anionic and nonionic incombination. The preferred nonionic surface active agents alkyl or(alkyl phenoxy polyoxyethylene ethanol) are composed of a hydrophobichydrocarbon portion and a hydrophilic portion. The latter is a chain of5 to oxyethylene units while the former has an alkyl group of 4 to 18carbon atoms which may be linked to the oxyet'hylene chain through thephenoxy group. Generally speaking, as the average length of thehydrocarbon chain in a monomer mixture increases, nonionic surfaceactive agents having a smaller number of oxyethylene groups should beused, i.e., those of greater oil solubility.

The compatibility of many such nonionic surface agents with thepolyvalent metal salts of this invention is not destroyed by thepresence of an anionic group. Such surface active agents, referred to asanionic-nonionic, normally have a hydrophilic anion, hydrophobic cationand a long-chain polyoxyethylene chain of 5 to 120 oxyethylene units.Typical useful surface active agents of this type are alkali metal saltsof alkyl phenoxy polyoxyethylene ethanol sulfate esters having 5 to 120oxyethylene units and the corresponding alkyl oxyethylene ethanolsulfate esters. For the purpose of this invention these anionic-nonionicsurface active agents can be considered to be nonionic surface activeagents and can be used interchangeably. In large measure, the selectionof surface active agent (or agents) for the present polymer is the sameas for many prior art emulsion polymerization systems.

In emulsion polymerization, the amount of surface active agent or agentsrequired, varies primarily with the concentration of monomers to behandled and to a minor extent with the choice of emulsifier, monomers,portion of monomers and catalysts. Generally, the amount of surfaceactive agent used in the polymerization mixtures will range from about 4to 25 of the total monomer weight. Lower concentrations in the range ofabout 1 to 4% by weight can be used. However, the emulsion must then bepost stabilized with sufficient surface active agent to preventcoagulation of the polymer upon addition of the polyvalent metalcompound or to prevent development of haze in the applied polishcoating. Somewhat the same principles apply in the selection of theamount of surface active agent as in the selection of the surface activeagent itself. The proportion must be sufficient to impart the necessarystability, desired rate of polymerization, and particle size.

As polymerization catalysts, there may be used one or more of theperoxidic compounds better known to act as free-radical catalysts whichhave at least some solubility in aqueous solution of the emulsifier orwhich are soluble only in the monomer phase. Among the useful catalytsfor the present type of copolymerization are the persulfates, ammonium,sodium and potassium salts, hydrogen peroxide and the perborates. Alsouseful, are the organic peroxides and hydroperoxides. These includebenzoyl peroxide, tertiary butyl hydroperoxide, (ii-isopropyl benzenehydroperoxide, cumene hydroperoxide, caproyl peroxide, methyl ethylketone peroxide, etc. Other free-radical catalysts are also useful, suchas azodiisobuty-ronitrile and other aliphatic azo compounds of the typehaving an acyclic azo group and an aliphatic carbon atom on eachnitrogen, at least one of which is tertiary. In part, the particularcombination of monomers governs the selection of the inorganic ororganic peroxidic catalysts since some monomers respond better to onevariety than they do to another.

The amount of peroxidic catalysts required is about proportional to theconcentration of monomers used. The usual range is 0.01% to 3% ofcatalyst with reference to the weight of the monomer mixture. Theoptimum amount of catalyst is determined in large part by the nature ofthe partcular monomer selected, including impurities (includingpolymerization inhibitors) which accompany particular monomers.

Frequently a promoter for the catalyst (sometimes called an acceleratoror adjuvant) is used to hasten the reaction at a sufficiently lowtemperature to avoid coagulation. The promoter may be a reducing agentand together with the peroxidic catalyst is frequently referred to as aredox system. Many examples of such systems are known and the promotersinclude ascorbic acid, and soluble sul fites, hydrosulfites,sulfoxylates, thiosulfates, and bisulfites. Examples of particularpromoters are sodium hydrosulfite, sodium metabisulfite, zinc or sodiumformaldehyde sulfoxylate, and calcium bisulfite. Polyvalent metal ionsare also used in small concentration, particularly ferrous iron in theform of ferrous ammonium sulfate at concen trations of a few parts offerrous ion per million.

The amount of promoter required varies, as is known, with thefree-radical initiator chosen and with the particular promoter. Theemulsifying agent also alfects somewhat the amount used as do theparticular monomers. At the outside, not more than 3% or less than 0.01%is used in these situations. The preferred range of ascorbic acid is atthe low end of this range up to about 0.5% while sulfites are usedpreferably in an amount of 0.2% to 1% Copolymerization is best effectedbelow about 95 C. The preferred range is 30 to 70 C., although slightlylower C.) temperatures are permissible. After most of the monomers havebeen converted to copolymer, temperatures even higher than 95 C. maythen be applied. In fact, after most of the monomers have beencopolymerized, the resulting emulsion copolymer system can be heated toboiling without breaking the emulsion. During copolymerization thetemperature can be controlled in part by the rate at which monomers aresupplied and polymerized and/ or by applied cooling.

The polymerization process can be carried out batchwise or continuously.It is possible to work entirely batchwise, emulsifying the entire chargeof monomers and proceeding with polymerization. It is usuallyadvantageous, however, to start with part of the monomers which are tobe used and add more monomer as polymerization proceeds. An advantage ofgradual or stepwise addition of monomers lies in reaching a high solidscontent with optimum control and maximum uniformity of product.Additional catalysts or additional components of the redox system may beadded as polymerization proceeds, and these can be used to control thespeed of reaction to avoid overheating.

Aconvenient method of carrying out the polymerization utilizing thepreceding principles comprises preparing separate pre-mixtures asfollows: (1) a catalystemulsifier pre-mixture; (2) a first monomerpre-mixture; and (3) a second monomer pre-mixture which contains thebalance of the monomers to be polymerized. If desired, third and fourthmonomer pre-mixtures may also be employed. In this method of performingthe reaction, the catalyst-emulsifier pro-mixture is preferably preparedin warm water to C.). To this, the first monomer pre-mixture is addedand the polymerization is initiated.

After the reaction becomes exothermic, the second monomer pre-mixture isadded over a time sufiicient to permit the temperature to be controlledthroughout the reaction. The same care is taken with any other monomerpre-mixtures. Additional catalysts and/or promoter is added whennecessary to maintain the reaction. Finally, the reaction is permittedor forced to go to completion, which is insured (1) by raising thetemperature to about C., and/or (2) by the addition of additionalcatalysts and/ or promoter.

In general, the preferred polymer emulsions resulting from the emulsionpolymerization of three monomer types are acidic because of theproportion of acid comonomer. These polymer emulsions can, if necessary,be adjusted to a pH of 3.5 to 7 with volatile alkali, such as morpholineor ammonia and/ or a non-volatile polyvalent metal salt of an organicacid. Many of the polyvalent metal salts, organic acid, in accordancewith this invention, serve well to buffer the emulsion in the pH rangestated. For example, zinc acetate solutions in water have a pH of 6.2 to6.7 depending on concentration. If the polymer emulsion has a pH morethan 7.0, it may be adjusted to a value below 7 with a suitable acid(e.g. hydrochloric acid, acetic acid, sulfuric acid) or with an acidmetal salt (e.g. zinc chloride or ammonium chloride).

The polymer emulsion can be shipped in either form, partiallyneutralized or not, to a floor polish formulator, or it can beformulated with the other ingredients of the floor polish immediatelyafter the formation of the polymer emulsion. Generally, the polymeremulsion is shipped after the addition of the previously describedpolyvalent metal salt of organic acid. If desired, emulsionpolymerization can be carried out in the presence of the polyvalentmetal salt. However, particle size control is somewhat difiicult.

Generally, the polyvalent metal salts are dispersed or dissolved inwater prior to their addition to the polymer emulsion. The solution ordispersion can then be added hot or cold. There is rarely a need toadjust the pH of the polyvalent metal dispersion because their aqueoussolutions act as a buffer in the desired pH range. The addition of thepolyvalent-metal, organic-acid salt to the polymer emulsion seems toaffect the emulsion as if the particle size of the polymer hadincreased. The final product may be filtered to remove coagulatedpolymer if desired.

The characteristics of a dried film of floor polish are improved by theaddition of various additives to the acidic polymer emulsion whichcontain polyvalent metal salt of an organic acid. One may add, forexample, a wax such as carnauba wax, candelilla wax, Fischer-Tropschwax, oxidized polyethylene wax, polyethylene emulsion, modi- -fiedMontan wax or ester wax, mixtures of rosin amine in polyethyleneemulsion, copolymers of ethylene and acrylate esters, etc. The primaryfunction of wax in a floor polish is to impart certain desirable filmcharacteristics, such as mar resistance, bulfability, flexibility, etc.Further, wax may also contribute to the soap-and-water and alkaliresistance of the applied polish.

However, unlike commercially available floor polishes, wax is notessential for the preparation of a suitable floor polish from thepolymer emulsions of this invention. Acceptable floor polishes have beenformulated without using any wax. Apparently, the combination ofnonionic surface active agents and polyvalent metal salt of organic acidis able to take the place of the wax. For a completely buffable floorpolish, wax is essential.

Other-additives, as are common in floor polishes, include methylCarbitol and/or tributoxyethyl phosphate which act as leveling agents,softeners (plasticizers) and coalescing agents, fluorinated compounds ofUS. Patent No. 2,937,098, such as FC-134 sold by Minnesota Mining andManufacturing Company, which serve as leveling aids, etc. These levelingaids and softeners are particularly important in this invention sincethe polymer emulsion is not film-forming at room temperature. Additivesmust be employed in order to give the floor polish the necessarycoalescing properties. Methyl Carbitol is particularly useful in thisinvention as a coalescing agent. Fugitive coalescing agents of this type(methyl Carbitol, ethyl Carbitol, butyl Carbitol) advantageouslycomprise from about to 60 parts by weight per 100 parts by weight ofpolymer solids in the floor polish. Surprisingly, relatively highconcentrations of coalescing agents of this type of softener and ofleveling agents have virtually no effect on the water resistance ordetergent resistance of the floor polishes of this invention.

The various ingredients of a door polish of this invention areformulated in water at about 8 to by Weight of total solidsconcentration with the aid of a nonionic surface active agent, such asone of the type described above which is suitable for preparing thepolymer emulsion. Then one or more leveling agents, coalescing agentsand/or plasticizers are added to the floor poiish, such as methylCarbitol, tributexyethyl phosphate or fluorocan bon surface activeagent. The floor polish is then adjusied, if necessary, to a pH of about5 to 6.8, preferably 6.0103. This pH range has been found to result infloor polishes having optimum properties.

The floor polishes of this invention can be removed from resilientflooring easily and without any deleterious effect on the substrate. Awide variety of removers are feasible. In general, the removers comprisewater, alkali and one or more water-miscible organic solvents. Bestresults have been obtained using a system having a pH of about 10 to 12with the alkalinity being provided by a detergent, preferably containingtrisodium phosphate, and a water-miscible organic solvent comprising oneor more water-soluble alcohols such as ethylene glycol, propyleneglycol, butoxyethoxy propanol, butoxyethanol, etc. In the absence ofwater-miscible organic solvent, the detergent cleans the floor polishsurface and does not remove the applied polish. Other types of removersare feasible such as those based on chelating agents or complexingagents. However, this invention is not to be considered limited in anymanner by the class of remover employed.

The following examples are merely illustrations and should not beconstrued as limiting the scope of this invention. In the example, theword parts refers to parts by weight.

Example I The following premixtures were prepared to be used in thepreparation of a preferred floor polish polymer of this invention.

Catalyst-emulsifier premixture: Parts dry weight Sodium salt of laurylpolycthoxysulfate,

C H (OCH CH OSO Na 6.52 Nonylphenyl ether of polyoxyethylene (10.5)

glycol (Tergitol NPX) 2.0

Tertiary butyl hydroperoxide .25

Water 130.5 First monomer premixture:

Styrene 27 Ethyl acr-ylate 14 Methacrylic acid 3 Second monomerpremixiure:

Styrene 25.25

Ethyl acrylate 10.0

Acrylonitrile 11.95 Third Monomer Premixture: Styrene 5.75 Promoter:

Ascorbic acid .10

Waer 40.0 Additional catalyst:

Tertiary butyl hydroperoxi-de .25

Water 10.0

The emulsifier-catalyst premixture was prepared in hot water in asuitable glass-lined reactor fitted with a stirrer and jacket. After thereactor was cooled to C., 15% of the first monomer premixture and of thepromoter premixture were added to the reactor over a 1 hour period whilemaintaining the exothermic reaction at 55-60 C. Half of the additionalcatalyst premixture was added half way through the addition of the firstmonomer premixture. The second monomer premixture and 20% of thepromoter premixture were slowly added to the reactor while maintainingthe reaction at 5560 C. Thirty percent of the additional catalystpremixture was added after the addition of second monomer premixture wascompleted. The third monomer premixture was next added and this wasfollowed by the addition of the remaining additional catalystpremixture. Then the polymerizaiion reaction was forced to completion byadding the remainder of the promoter premixture over a thirty minuteperiod and increasing the reaction temperature to between and C. Theresulting 36% total solids polymer emulsion had less than 0.05%coagulurn and a Tg of 71.5 C.

The polymer emulsion was diluted with water to 30% by weight totalsolids and compounded with additional surface active agent, fugitivecoalescing agent and polyvalent metal salt of an organic acid in thefollowing proportions:

POLYMER BLEND Active Weight Wet Weight The resulting composition wascompletely stable. For use in the examples following, the resultingpolymer blend was diluted with water to 14% active ingredients. Thecomposition had a Tg of 45 C.

Example II This example illustrates the preparation of dry-bright floorpolish from the polymer blend of Example I. A nonionic-anionie waxemulsion was prepared by melting 47.1 parts by weight polyethylene and52.9 parts by weight Hoechst KSL ester wax together at 220 F. Eight andfour-tenths parts by weight of polyox-yethylated fatty alcohol (EmulphorObi-870) (or Hoechst emulsifier 2106), 9.4 parts by weight (IgepalCO630) nony'lphenoxypolyoxyethylene (9.5) alcohol, 3.7 parts by weightsorbitan trioleate and 3.3 parts by weight aqueous KOH (0.66 part drysolids) were blended into the melt with agitation. The resulting meltwas slowly stirred into 748.1 parts by weight water at 205-210 F. usinggood agitation and then cooled rapidly to form a 14% by weight waxemulsion.

The dry-bright floor polish was prepared by adding, in order, 7.5 partsby weight of the described wax emulsion (14% by weight solids), 0.9 partby weight tributoxyethyl phosphate, 2.0 parts diethylene glycolmonomethyl ether and 0.5 part by weight cationic surface active agenthaving a long fluorocarbon group and a solubilizing organic group(EC-134) (1% by weight solids) with good agitation to 92.5 parts byweight of the polymer blend of Example I (14% by weight activeingredients).

Example III An excellent buffable floor polish was prepared in themanner described in Example II except that the concentration of waxemulsion (14% by weight solids) was increased to 30 parts by weight andthe polymer blend concentration (14% by weight solids) was decreased to70 parts by weight.

Example IV This example illustrates that the floor polishes of thisinvention, when compared to typical acrylic polishes, as well as to bothhousehold and industrial acid-sensitive (polishes based on aminoalkylacrylates) types were equal to or superior in performance. Table Isummarizes the results of conventional bench tests.

hours showed complete removal of all commercial products evaluated andonly slight discoloration of the prod- TABLE I Dry-Bright BufiableHousehold Household Industrial Property Tested Polish of Polish oiDry-Bright Dry-Bright Bufiable,

Example II Example III Acrylic .Aeid- Acid- Sensitive Sensitive GlossExcellent. Excellent- Excellent- Very good Excellent. Leveling. Verygood Very good -do- .do Very good. Haze. None. None None. None. one.Craze .do .do .do .do Do. Waterspotting (1 hr.):

Initial. Excellent. Excellent.. Very good Very good. Excellent. Final.do .do Excellent. Excellent- Do. Recoatability ($6 hr.):

Initial Gloss Excellent .do Very good Do. Final Gloss Increased-Increased- Same. Increased. Wet Abrasion Resistance Excellent.Excellent. Excellent Excellent.

Example V ucts of this invention. To simplify the following table,

those early results are not shown.

TABLE II.TIME (IN DAYS) REQUIRED TO ACHIEVE COMPLETE DETERGENTRESISTANCE Solid Solid Liquid Liquid Liquid Liquid Polish SubstrateDetergent Detergent Household Detergent Detergent Detergent V (ph 10) V(pH 12) Detergent X (pH 9.4) Y (pH 9.5) Z (pH 9.6)

W (pH 9.5)

I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 7 1 1 1 1 1 3 11 1 1 1 3 1 sp t 1 1 1 1 1 1 Vinyl asbestos.-- 7 14 CommercialIndustrial Acid-Sensitive Bufiable Vinyl (1) i (1) 1 Polish. Rubber-.-(1) i i (I) Asphalt 14 14 7 Vinyl asbestos... 14 14 Commercial HouseholdAcid-Sensitive Dry- Vinyl (1) (i) i 14 Bright Poiish. Rubber 0) A p 0) 714 0) 1 Indicates that the polish filmwas still affected by thedetergent, even after two weeks. The above data clearly show thesuperior detergent resistance of the floor polishes of this invention.

sistance of floor polishes of this invention. Special bench tests todetermine detergent-resistance were run in the following manner: Vinyl,rubber, vinyl asbestos and asphalt tile panels were coated with testpolish using a gauze applicator and allowed to dry. Detergent resistancewas checked by applying 1 ml. of detergent, allowing it to remain for 3minutes, rinsing the panel under running water and then wiping it drywith a soft towel. The residual effect of the detergent on the polishfilm was then recorded, at 1, 3, 7 and -14 days.

The special bench tests showed that the conventional commercial acrylicpolishes had no resistance to detergents. The commercial acid sensitive'polishes (based on aminoalkyl acrylates) particularly the industrialtype, had some but not complete resistance after a two week EMMPLE VIThis example illustrates that the floor polishes of this invention canbe easily removed from flooring materials using a suitable remover. Forthis evaluation, three household polish removers and three heavy-dutyindustrial strippers were chosen. A special remover having a pH of 11.0was also formulated by adding 6.0 parts by weight trisodium phosphate,10.0 parts by weight ethylene glycol, 3.0 parts by weight butoxyethoxypropanol to 81 parts by weight water. The coated tiles were aged for twoweeks and then tested by applying 1 ml. of remover, allowing it toremain for 3 minutes, rinsing with running water and wiping dry with asoft towel. The residual effect of the remover on the film was observedand recorded in Table III below.

TABLE III.-FLOOR POLISH REMOVER TEST RESULTS Liquid Floor Polish RemoverRemover of Polish Substrate Household Industrial this Example D U P D PU R Bufiable Polish of Example III v g g E g g U U U U U U R D U P D D UR Dry-Bright Polish of Example II vinylasbestos g g g g g g Asphalt D UU U U U R Key.R Removed; P Partially removed; D Discolored; UUnafiected.

test period, while the polishes of this invention attained completeresistance to most detergents after 24 hours of drying time. Table IIcompares the effect of various de- The above data illustrates that thepolishes of this invention can be removed with a suitable stripper. Thedata also indicate to some extent the resistance of the tergents on theapplied floor polishes. Tests at 2, 4, and 8 floor polishes of thisinvention to removal with commercial strippers. However, while benchtests on individual tiles are used to compare the capabilities of aremover, most industrial removers are used on the floor with anindustrial buffing machine and nylon stripping pad. There are manyspecial industrial polish removers available and it is quite possiblethat one or more of them will be effective in removing the polishes ofthis invention.

Example VII The bufiable polish of Example III and a standard commercialbuffable floor polish noted for its high performance were applied inseveral diverse locations by an established Industrial MaintenanceService. Test areas included a local department store, a new apartmentbuilding and an industrial office building. In all locations, thebutfable polish of this invention exhibited superior initial glosswithout buffing. The standard butfable polish exhibited the same levelof gloss only after buffing.

Using an accelerated maintenance program, these polishes were cleanedwith a mop every other night using hot soapy water, followed by light'bufling. After three weeks of this maintenance, the polishes weresubjected to machine cleaning. At this point, a heavy duty remover wasemployed and used at the suggested concentration for cleaning. Followingthis procedure, both polishes were buffed. The polish of this inventionwas restored to its original appearance, while the commercial polish wasremoved.

Essentially the same results were obtained in a comparison of adry-bright polish of this invention (the polish of Example II) andstandard commercial dry-bright polish.

Similar results were obtained in a comparison of the buffable polishesof Example III and the dry-bright polish of Example II with commercialacid-sensitive polishes.

Example VIII This example illustrates the use of various otherpolyvalent metal compounds in the floor polishes of this invention. Anumber of dry-bright polishes were formulated in the same manner as thedry-bright polish of Example 11 except that the zinc acetate used in thepolymer blend of Example I was replaced by an equal weight of (a)aluminum acetate, (b) cadmium acetate, (c) barium aceate, (d) calciumsalt of ethylenediamine tetraacetic acid and (e) a control containing nopolyvalent metal compound. The dry-bright polishes were applied tosuitable tile and permitted to age for one week. Detergentresistance wasevaluated by applying 1 ml. of tripolyphosphate detergent (Spic andSpan), allowing it to remain for 3 minutes, rinsing the panel underrunning water, and then wiping it dry with a soft towel. None of thepolishes was affected by the detergent. Each of the polishes, (a) to (d)was removed with the special remover of Example VI while polish (e),which contained no polyvalent metal compound, could not be removed withthis remover. The two polishes based on aluminum acetate and cadmiumacetate exhibited particularly high gloss.

Example IX This example illustrates the preparation of a fioor polishusing a polymer having a relatively high concentration of acid monomer.It also illustrates post stabilization of the polymer emulsion withadditional nonionic surface active agent. The polymer emulsion wasprepared using the following premixtures:

Catalyst-emulsifier premixture. Parts dry weight First monomerpremixture:

Styrene 27 Ethyl Acrylate 15.5 Methaerylic acid 15 Second monomerpremixture (with additional catalyst):

Styrene .5

Acrylonitrile 17.0

Tertiary butyl hydroperoxide 0.15 Promoter Ascorbic acid 0.16

Water 35 Additional emulsifier: Lauryl ether of polyoxyethylene (23)glycol (Brij35) 4.5

The emulsifier-catalyst premixture was prepared in hot water in asuitable glass-lined reactor fitted with a stirrer and jacket. The firstmonomer premixture was then added to the reactor followed by 12.5% ofthe promoter. An additional 37.5% of the promoter was added over a peri-0d of one hour while the reaction temperature was permitted to rise from30 C. to about 65 C. The second monomer premixture and the rest of thepromoter was added over a period of one hour while maintaining thereaction at between 60 and C. The polymerization was forced tocompletion by raising the reaction temperature to C. for one hour. Thereactants were cooled to room temperature, and the additional emulsifierwas added. The resulting 36% total solids polymer emulsion had less than0.05% coagulum and a Tg of 94 C.

A polymer blend was prepared from the emulsion in the manner describedin Example I and a dry-bright polish formulated in the manner describedin Example II. The polish which was applied to a suitable substrate, hadexcellent gloss. After one week, the film of polish was resistant totrisodium polyphosphate detergent (Spic and Span), but was easilyremovable with the special remover of Example VI. A second floor polishwas formulated in the same manner, except that the floor polish did notcontain any polyvalent metal salt of an organic acid. The polish was notresistant to the trisodium polyphosphate detergent.

Example X This example illustrates the preparation of a floor polishusing a polymer having an acid monomer concentration intermediatebetween the polymer of Examples I and IX. The following premixtures wereprepared:

Emulsifier-catalyst premixture: Parts dry weight Sodium salt of laurylpolyethoxysulfate 4.0 Nonylphenyl ether of polyoxyethylene (10.5)

glycol (Tergitol NPX) 5.0 Tertiary butyl hydroperoxide 0.15 Water 150.6

First monomer premixture (with catalyst):

Styrene 22.0 Ethyl acrylate 15.0 Methacrylic acid 10.0 Tertiary butylhydroperoxide 0.15

Second monomer premixture (with additional catalyst): Styrene 36.0Acrylonitrile 17.0 Tertiary butyl hydroperoxide 0.15

Promoter:

Ascorbic acid 0.16 Water 30.0

The polymerization was carried out in essentially the manner describedin Example I. Fifteen percent of the first monomer premixture was addedto the emulsifier premixture followed by one-sixth of the promoter. Theremainder of the first monomer premixture and one-third of the promoterwere added gradually over a period of one hour. Thirty minutes later,the gradual addition of the second monomer premixture and one-third ofthe promoter was started. The addition was completed in one 17 hour.Thirty minutes later the reaction was forced to completion by adding theremainder of the promotor and raising the reaction temperature to 85 C.The resulting 36% total solids emulsion had less than 0.1% coagulum anda Tg of 955 C.

A polymer blend and dry bright floor polish were formulated in themanner described in Examples 1 and II. The applied floor polish hadexcellent gloss, resistance to detergent and was removable with thespecial remover of Example VI. A dry-bright floor polish formulated inthe same manner, but without polyvalent metal salt of an organic acid,was partially removed by detergent.

Example XI This example illustrates the preparation of another preferredpolymer of this invention. The following premixture was prepared:

Catalyst-emulsifier premixture: Parts dry weigh Sodium salt of laurylpolyethoxysulfate 6.5 Nonylphenyl ether of polyoxyethylene glycol(Tergitol NPX) .0 Tertiary butyl hydroperoxide 0.15 Water 208.2

First monomer premixture (with catalyst):

Styrene 27.0 Ethyl acrylate 15.5 Methacrylic acid 3.0 Tertiary butylhydroperoxide 0.15

Second monomer premixture (with additional catalyst):

Styrene 35.5 Acrylonitrile 17.0 Tertiary butyl hydroperoxide 0.15

Promoter:

Ascorbic acid .16 Water 40.0

The polymerization was carried out in the manner described in Example X.The 30% total solids polymer emulsion had less than .2% coagulum and hada Tg of 88 C.

An aqueous solution of the zinc acetate (15.91 parts, 4 parts dryweight), 9.95 parts Tergitol NPX and 18 parts methyl Carbitol were addedto 51.19 parts water. This solution (22.2 parts by weight) was thenadded to 77.8 parts by weight of the 30% total solids polymer emulsionof this example. This blend, 28.5% total solids, was diluted to 14%solids by adding 50.9 parts water to 49.1 parts of the blend.

A dry-bright floor polish was formulated by mixing, in order, with goodagitation 87 parts of the 14% total solids polymer blend, 13 parts ofthe 14% total solids wax emulsion of Example II, 0.9 part tributoxyethylphosphate, 0.5 part (1% total solids) FC134 and 2 parts diethyleneglycol monomethyl ether. The floor polish exhibited excellent gloss,excellent detergent-resistance and excellent removability with thespecial remover of Example VI.

Example XII This example illustrates the preparation of a polymer havinga relatively high level of soft monomer. The following premixtures werepolymerized by the method of Example X:

Emulsifier-catalyst premixture:

Parts by weight Sodium salt of lauryl polyethoxysulfate 4 5 Tertiarybutyl hydroperoxide Second monomer premixture (with additionalcatalyst): Styrene 45.0 Tertiary butyl hydroperoxide 0.15

18 Promoter: Parts by weight Ascorbic acid 0.16 Water 40 The 30% totalsolids polymer emulsion had less than .3% coagulum and a Tg of 30.5 C.

A polyethylene wax emulsion for use with this polymer was prepared bymelting parts polyethylene, 8 parts sorbitan trioleate and 10 partsnonylphenyl ether of polyoxyethylene (9.5) glycol (Igepal CO-630)together at 220 to 230 F. Seven parts of aqueous KOH (1.4 parts drysolids) was then added. The resulting hot melt was poured intosufficient hot water (200 F.) with-good agitation to form a 21% totalsolids wax emulsion.

After the polymer emulsion had been diluted to 15% total solids, thefollowing ingredients were added to 100 wet parts of the polymeremulsion:

Zinc acetat (15% total solids aqueous solution) parts.-- 15 Polyethylenewax emulsion (21% total solids) parts 7.2 Tributoxyethyl phosphate ml 1This composition was modified by adding small increments of a 15 aqueoussolution of surfactant (nonylphenyl ether of polyoxyethylene glycol,Tergitol NPX).

Example XIII The polymerization reaction of Example XII was repeatedexcept that the methacrylic acid content was increased from 2.5 to 3.0parts. The 30% total solids polymer emulsion had less than .1% coagulumand a Tg of 28.5 C.

The polymer emulsion Was diluted to 15 total solids. One hundred partsof this polymer emulsion were compounded with 10 parts of a 15% solidsaqueous solution of nonylphenyl ether of polyoxyethylene (10.5) glycol(Tergitol NPX), 7.2 parts of the polyethylene wax emulsion of ExampleXII, 15 parts aqueous Zinc acetate (15 total solids) and 1 parttributoxy ethyl phosphate. The applied polish was somewhat tacky andtended to pick up dust. This tackiness was cured by increasing the zincacetate concentration to 25 parts (15% total solids). However, theapplied polish still tended to pick up dirt at a relatively rapid rate.

Example XIV This example illustrates the preparation of two closelyrelated floor polish polymers composed of the same monomers in slightlydifferent proportions. The following premixtures were prepared:

Parts dry weight TABLE IV in the absence of polish coalescing agents andpolish plasticizer.

2. An acidic polish composition comprising as its essentialingredients 1) a wax, (2) an aqueous emulsion of a synthetic additionpolymer comprising (a) at least one hard monomer selected from the groupconsisting of monovinyl aromatic compound, alpha,beta-ethylenicallyunsaturated nitrile and alkyl ester of alpha,beta- Components, Wet Partsof Ingredients:

Polymer A at 15% solids Polymer B at 15% solids 100 Nonylphenyl ether ofpolyoxyethylonc (10.5)

glycol (Tcrgitol NPX) at 15% solids 11. Polyethylene wax emulsion at 21%solids Zinc acetate at 15% slids Tributoxyethyl phosphate, ml.

Polish gloss I Glossy. 2 Slight haze.

Optimum gloss was obtained with polymer B using 11 parts of thepolyoxyethylene glycol ether per 100 parts polymer emulsion at a zincacetate level of 15 to 25 parts per 100 parts polymer emulsion. Optimumgloss was obtained with polymer A, which was somewhat softer thanpolymer B, using 7 parts of the polyoxyethylene glycol ether per 100parts polymer emulsion at a zinc acetate level of 15 to 25 parts per 100parts polymer emulsion. For optimum gloss at 40 parts zinc acetate per100 parts polymer emulsion, polymer A required 9 parts of thepolyoxyethylene glycol ether per 100 parts polymer emulsion. Polishesbased on polymer emulsion A tended to pick up more dirt and dust thanthe polishes based on polymer emulsion B. However, as the concentrationof polyvalent metal salt in polishes based on polymer emulsion Bincreased, there was improvement in this property.

While this invention is directed to floor polishes having both excellentdetergent resistance and ease of re moval, the invention is susceptibleof broader application. To some extent there has been a demand in recentyears for floor polishes which can be removed from the flooring withconventional detergents. Acidic fioor polishes of the type describedherein offer another solution to this problem. Ease of removal isobtained by employing a suitable polymer emulsion of the type describedherein, preferably a polymer containing to by weight free carboxylcontaining monomer, wax and a polyvalent metal salt of an inorganic acidsuch as zinc chloride, zinc nitrate, calcium chloride, magnesiumchloride, etc. The polyvalent metal salt of an inorganic acid functionsas a leveling agent permitting the omission of alkali-solubl resin andfacilitates the removal of the applied polish from the flooring.

Since many embodiments may be made of this inven tion, and since manychanges may be made in the embodiments described, the foregoing is to beinterpreted as illustrative only, and the invention is defined by theclaims following hereafter.

What is claimed is:

1. An acidic polish composition comprising as its essential ingredients(1) a. wax, (2) an aqueous emulsion of a synthetic addition polymercomprising (a) at least one hard monomer selected from the groupconsisting of monovinyl aromatic compound, alpha,beta-ethylenicallyunsaturated nitrile and alkyl ester of alpha,beta-ethylenicallyunsaturated carboxylic acid and (b) 0.5 to by weight ofalpha,beta-ethylenically unsaturated acid monomer, said polymer having aTg of at least 25 C. at an emulsifier content of 5% by weight of thepolymeric component and (3) a water dispersible polyvalent metal salt ofan organic carboxylic acid having from 1 to 4 acid groups in aconcentration sufiicient to impart leveling and selective removabilityto said polish composition, said composition being non-film forming atroom temperature ethylenically unsaturated carboxylic acid and (b) 0.5to 25% by weight of alpha,beta-ethylenically unsaturated acid monomer,said polymer having a Tg of at least 40 C. at an emulsifier content of5% by weight of the polymeric component and (3) a water dispersiblepolyvalent metal salt of an organic carboxylic acid having from 1 to 4acid groups in a concentration sufificient to impart leveling andselective removability to said polish composition, said compositionbeing non-film forming at room temperature in the absence of polishcoalescing agents and polish plasticizer.

3. The composition of claim 2 wherein said polyvalent metal compoundcomprises from 5 to 100 parts by weight per 100 parts by weight ofpolymeric component.

4. The composition of claim 2 wherein said polyvalent metal compoundcomprises from 10 to 25 parts by weight per 100 parts by weight ofpolymeric component and said composition comprises nonionic surfaceactive agent in a concentration of about 0.5 to 2 parts by weight perpart by weight of polyvalent metal compound.

5. The composition of claim 4 wherein said polyvalent metal salt of anorganic acid comprises at least one salt of a metal selected from thegroup consisting of zinc, aluminum and cadmium.

6. The composition of claim 4 wherein said polyvalent metal salt of anorganic acid comprises zinc acetate.

7. The composition of claim 2 wherein said polish contains from 10 to 60parts by weight fugitive coalescing agent per 100 parts by weight ofaddition polymer.

8. The composition of claim 2 wherein said synthetic copolymer comprisesfrom 60 to by weight of a hard monomer, from 10 to 35% by weight of asoft monomer and from 0.5 to 15 by weight of an alpha,beta-ethylenically unsaturated free-carboxyl-containing monomer.

9. The composition of claim 8 wherein said polyvalent metal salt of anorganic acid comprises from 10 to 25 parts by weight per parts by weightof polymeric component and said composition comprises nonionic surfaceactive agent in a concentration of 0.5 to 2.0 parts by weight per partby weight of polyvalent metal salt.

10. The composition of claim 9 wherein said polyvalent metal saltcomprises an acetic acid salt of a metal selected from a groupconsisting of zinc, aluminum and cadmium.

11. An acidic polish composition comprising as its essential ingredients(1) a water-dispersible polyvalent metal salt of an organic acid havingfrom 1 to 4 acid groups in a concentration sufficient to impart levelingand selective removability to said polish composition (2) an aqueosemulsion of a synthetic addition polymer, said polymer having a Tg of atleast 40 C. at an emulsifier content of 5% by weight of the polymericcomponent, said synthetic addition polymer comprising from 60 to 21 85%by weight of a hard monomer of which at least 50% by weight is selectedfrom at least one monomer of the class consisting of monovinyl aromaticcompound and alpha,beta-ethylenically unsaturated nitrile, from to 35%by weight of a soft ester of an alpha,beta-ethylenically unsaturatedmonocarboxylic acid and from 0.5 to by weight of analpha,beta-ethylenically unsaturated free-carboxyl-containing monomerand (3) wax.

12. The composition of claim 11 wherein said monovinyl aromatic compoundcomprises styrene and said alpha,beta-ethylenically unsaturated nitrilecomprises acrylonitrile.

13. The composition of claim 11, wherein at least 50% by weight of saidpolymer is selected from at least one monomer of the class consisting ofmonovinyl aromatic compound and alpha,beta-ethylenically unsaturatednitrile.

14. The composition of claim 12 wherein the metal ion of said salt isselected from the group consisting of zinc, aluminum and cadmium.

15. The composition of claim 14 wherein said polyvalent metal saltcomprises from about 10 to 25 parts by weight per 100 parts by weight ofsynthetic polymeric material and said composition comprises nonionicsurface active agent in a concentration of 0.5 to 2.0 parts per part byweight of polyvalent metal salt.

16. The composition of claim 15 wherein said polyvalent metal saltcomprises zinc acetate.

17. The composition of claim 11 wherein the concentration of wax issufiicient to make said composition a buifable floor polish.

18. The process for treating and preserving resilient flooring whichcomprises applying a polish composition comprising as its essentialingredients (1) a wax, (2) an aqueous emulsion of a synthetic additionpolymer comprising (a) at least one hard monomer selected from the groupconsisting of monovinyl aromatic compound, alpha, beta-ethylenicallyunsaturated nitrile and alkyl ester of alpha,beta-ethy1enicallyunsaturated carboxylic acid and (b) 0.5 to 25% by weight of analpha,beta-ethylenically unsaturated acid monomer, said polymer having aTg of at least C. at an emulsifier content of 5% by weight of thepolymeric component and (3) a waterdispersible polyvalent metal salt ofan organic carboxylic acid having from 1 to 4 acid groups in aconcentration sufiicient to (a) ionically cross-link sufficient freeacid groups in said addition polymer to impart selective detergentresistance to said polish layer and (b) permit removal of the polishlayer with suitable alkaline remover.

References Cited UNITED STATES PATENTS 2,343,089 1 2/ 1944 Smith.

2,754,280 7/ 1956 Brown et al. 260-296 2,923,692 2/ 1960 Ackerman et al.26028.5 2,971,934 2/1961 Brown et al 26028.5 3,026,281 3/ 1962 Harren etal.

3,308,078 3/1967 Rogers et al. 26027 3,328,325 6/1967 Zdanowski 26028.5

0 JULIUS FROME, Primary Examiner.

B. A. AMERNICK, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,403,119 September 24, 1968 Charles I Sullivan et al It is certifiedthat error appears in the above identified patent and that said LettersPatent are hereby corrected as shown below:

Column 2, line 27, "glass" should read gloss Columns 14 and 15, TableII, last column, 14th figure down, l4" should read (1] Signed and sealedthis 30th day of March 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E SCHUYLER, JR.

Attesting Officer Commissioner of Patents

